local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Workspace = game:GetService("Workspace")

local monstersFolder = ReplicatedStorage:WaitForChild("Monsters")
local mutatedFolder = ReplicatedStorage:WaitForChild("MutatedMonsters")

local function isNormalMonster(name)
	return monstersFolder:FindFirstChild(name) ~= nil
end

local function isMutatedMonster(name)
	return mutatedFolder:FindFirstChild(name) ~= nil
end

local function addHighlight(model, mutated)
	if model:FindFirstChild("EntityHighlight") then return end

	local hl = Instance.new("Highlight")
	hl.Name = "EntityHighlight"

	hl.FillTransparency = 1
	hl.OutlineTransparency = 0

	if mutated then
		hl.OutlineColor = Color3.fromRGB(120, 0, 0)
	else
		hl.OutlineColor = Color3.fromRGB(255, 0, 0)
	end

	hl.Adornee = model
	hl.Parent = model
end

local function check(obj)
	if not obj:IsA("Model") then return end

	if isNormalMonster(obj.Name) then
		addHighlight(obj, false)

	elseif isMutatedMonster(obj.Name) then
		addHighlight(obj, true)
	end
end

-- existing monsters
for _, obj in ipairs(Workspace:GetDescendants()) do
	check(obj)
end

-- future monsters
Workspace.DescendantAdded:Connect(function(obj)
	task.wait(0.1)
	check(obj)
end)